Over the last number of years of disc brakes have proven very popular for cars and in most cases are provided as standard equipment on at least the front wheels. These brakes often include an anti-lock braking feature to provide maximum braking effect without lock up. This typically increases the heat required to be dissipated by the system.
The auto industry has also almost completely shifted to front wheel drive cars and the space available at the front wheels has been reduced and, in many cases, the size of the brake components has been reduced.
Many car braking systems, during even normal use of the car, will cause the disc rotors to become very hot leaving them vulnerable to brake fade and also vulnerable to damage from high temperature warping or high temperature stress. Anti-lock braking systems also contribute to the problem, in that, the brakes do not lock and, therefore, the brakes continue to absorb a large amount of heat during heavy braking.
Another factor to consider in vehicle brakes is the weight of the rotating braking member as this can appreciably effect the gas mileage of the vehicle. It is desirable to provide a brake system which is relatively light weight. Unfortunately, this normally affects the ability of the brake system to absorb heat energy without subjecting the braking system to temperatures where failure or damage to the braking system are likely to occur. With braking systems, the energy required to brake the vehicle is essentially transferred into heat absorbed by the braking system and eventually transferred to the surrounding air. There are a number of braking systems which are ventilated to improve the amount of heat which is transferred to the surrounding air.
In recent years, there have been a number of high temperature, lightweight, aluminum composite materials and there have been a number of attempts to design a braking system which has the rotating braking member, for example the disc, made of this high temperature composite material. Unfortunately, these prior disc systems do not have sufficient ability to absorb the heat produced during the braking and effectively distribute this heat to the surrounding air to maintain a satisfactory operating temperature of the braking system. These high temperature aluminum composite materials, to date, have not worked satisfactory in a braking system involving disc brakes.
Ring brakes as opposed to a disc brake have a ring braking member where the actual braking member is at a fixed radial distance from the axis of rotation. The ring braking member has opposed inner and outer braking surfaces and a caliper arrangement is used to apply force to these braking surfaces. By applying force to both braking surfaces, the problems associated with the high strength and high weight of a drum-type braking arrangement is avoided.